Hydraulic gear of the positive displacement type



April 23, 1946. J, ||,v DQRAN 2,399,008

HYDRAULIG GEAR oT THE TosITIvE DIsPLAcEMENT TYPE Filed Aug. 22, 1942 s sheets-sheet 1 Fi .1.' f

Inventor: J'ol'rw H Dor'an;

l-hs Attorney.

April 23, 1946 J. H. DoRAN 2,399,008.

HYDRAULIC GEAR 0F THE POSITVB DISPLACEMENT TYPE l Filed Aug. 22, 1942 5 Sheets-Sheet 2 i Inventor:

John H.Dor`an,

April 23, ,1946, H, DQRAN.` Y 2,399,008

HYDRAULIC GEAR 0F THE PoslTIvE DISPLACEMENT TYPE lfiled Aug. 22,`1942 3 Shets-Sheet 5 nl! Ilml Il Ill lll John H. Doran,

y ggf/Attorney.

Patented Apr. 23, 1946 HYDRAULIC GEAR oF THE rosr'rivE, msrLAcEMEN'r Tyra John H.. Doran, Scotia, N. Y., assigner to General Electric Company, a corporation of New York Application August 22, 1942, sensi No. atasco' 1 ciaim. (ci. ros-icc) I T he present invention relates to hydraulic gears of the positive displacement type such as are used as pumps for pumping liquid and as motors and hydraulic couplings.

The object of my invention is to provide an improved construction of such Ahydraulic gears of the `positive displacement type whereby better eiciency and economy are attained.

For a consideration of what I believe to be novel and my invention, attention is directed tothe followmg description and the claim appended thereto in connection with the accompanying drawings.

In the drawings Fig. 1 illustrates a `sectional View of a hydraulic gear embodying my invention; Fig. 2 is a section along line 2-2 of Fig. 1,

Fig. 1 being a section along line I-I of Fig. 2; Fig. 3 is a perspective View of the arrangement shown in Fig. 1; and Figs. 4 and 5 illustrate a modification according to my invention, Fig. 4 being a section along line dof Fig. 5 and Fig. 5 a section along lines 5 5 of Fig. 4.

In lthe following 'I shall describe the embodiment disclosed in Figs. l to 3 as a pump with the various gears rotating in a deiinite direction although, as will become apparent from the folloW- ing,the hydraulic gear maybe operated either as apump or a motor and the gears may be rotated in either direction in which case an inlet during operation in one direction becomes an outlet or discharge during operation in the opposite direction.

The hydraulic gear or pump of Figs. 1 to 3 has a cylindrical casing I 0 with an inner bottom or mounting plate II integrally formed therewith. An outer bottom plate I2 is secured to the inner plate I I by means including studs I3. A cover or top plate I4 is fastened' to thecylindrical cas-,- ing by a plurality of bolts I5. -The bottom plate and the top plate I4 formcentral cylindrical extensions or bearings I 6 and I1 respectively. A

central or sun gear I8 is disposed within the casing and secured to a shaft I9 supported on the bearing I6. The gear I8 mesheswith a plurality of planetary gears, in the present instance three planetary gears 20,-2I and 22 circumferentialiy uniformly spaced about the sun gear I8. Each gear has a shaft 23 which on oneV side of the gear is mounted in a bearing formed by the inner bottom plate I Iy and on the other side of the gear is mounted in a bearing formed by a plate 24. An

upper extension 25' of the shaft I8 is supported in l acentral bearing formed by the plate 24.

The aforementioned studs I3 are likewise secured in the plate 24. Each stud I8 passes 55 and the blocks dene through one of three spacer blocks 2t, 2i and 28. These blocks may be integrally formed with one of the platesl II and 24. They provide a xed spacing between these plates. The planetary gears 28, 2i, 22 mesh with an outer or ring searing 2i,

concentrically disposed within the casing i@ and provided with an upper cylindrical extension 30 secured to a disk 3i by avplurality of bolts-82. The disk 3i is fastened to a shaft 33 supported on the bearing Il.

The arrangement so far described is similar to a planetary gearing having a sun gear, a plurality of .planetary gears and of the sun gear is transmitted through the planetary gears to the outer gear, causing the sun gear and Vice-versa. Rotation of the sun gear shaft I9 at a xed speed causes slow rotation of the outer gear and the shaft 33, and rotation of shaft 33 with the outer gear at aixed speed causes faster rotation o f the sun gear and the Each of the spacer blocks 2t, 2l and 28 has a plurality of cylindrical surfaces, each concentric with anadjacent gear. Thus (Fig. 2) the bloei: 28 has a first cylindrical surface 3d concentric with the outer gear 2t, a second cylindrical surface 35 concentric with the planetary gear 2li, a third cylindrical surface 35 concentric with the sun gear I8, and a fourth cylindrical surface 3i concentric with the planetary gear 22. The gears spaces between them; more particularly the sun gear, the planetary gears and the blocks `fiormspaces il to S6 inclusive. The planetary gears," the ring gear and the blocks form spaces 41 to 52 inclusive; the space M being formed by the sun gear, the planetary gear 22 and the block 28; the space i2 being formed by the sun gear, the block 28 and the planetary gear .20; the space 41 being formed between the plane- A2i and the block 28:

form a chamber 55.'vlv` The aforementioned spaces with even numbers 42, 44, 46,48, 50 and 62 communicate with the chamber through openings 55 .in the plate 24..v The cylindrical extension an outer gear. 'Rotation rotation of' the latter in the opposite direction from that of 30 has a plurality of openings 51 establishing communication between the chamber 55 and an annular chamber 58 between the ring gear and the casing I0. The chamber 58 is connected to a conduit 59 and the chamber 53 is connected to a conduit 60. The arrangement may be operated as a pump by rotating either of the shafts I9 and 33. Let us assume that the shaft I9 is rotated in clockwise direction or the shaft 33 is rotated in counterclockwise direction. During such operating condition, the gears will rotate in the directions indicated by arrows in Fig. 2. The conduit 60 then forms the inlet conduit for receiving liquid and the conduit 59 forms an outlet of discharge conduit for discharging liquid. The liquid conducted through the inlet conduit 60 into the chamber 53 is forced or induced by the pumping action of the various gears into the inner spacesor chambers 4I, 43 and 45 and into the outer spaces or chambers 41, 49 and 5I. By the pumping action of the gears the liquid is forced from said inner and outer spaces'or` chambers into the remaining spaces or chambers 42, 44, 46 and 48, 5U and 52. From the latter the liquid is forced through the openings 56 in the plate 24 into the chamber 55 whence the liquid is .conducted through the openings 30 into the outer annular chamber ,58 to be discharged therefrom through the outlet conduit 59.

Thus, with an arrangement as described above.

the combination of a sun gear with three planetary gears meshing with the sun gear and an outer ring gear, twelve spaces or chambers are formed between adjacent portions of the gears and spacer blocks located between them.V During operation, six of these twelve spaces act as inlet or receiving spaces or chambers and six act as outlet or pressure spaces or chambers.l The six inlet spaces are connected to a pump inlet chamber and the six outlet spaces are connected to a pump outlet or discharge chamber.v Three of the six inlet spaces or chambers are formed between the sun gear and 'the planetary gears and the other three of the inlet spaces are formed between the planetary gear and the ring gear. Likewise, three of the outlet spaces are formed between the sun gear and the planetary gears and the other three outlet spaces are formed between the planetary gears and the ring gear. Each 0f the spaces, as pointed out above, is partly dened by a surface of one of the spacer blocks 26. 21 and 28. Liouid flowing, for example, into the inlet space 4| during operation is partly forced intol the inner outlet space 42 and partly into the outer space 52, as indicated b v arrows. Likewise, liquid owing into the inlet space or chamber 41 during operation is partly forced into the inner outlet space 42 and partly into the outer outlet space 52. In other words, during operation the liquid owing into an inner or an outer inlet space or chamber is forced therefrom partly into an inner and partly into an outer outlet space or chamber.

With an arrangement according to my invention, as illustrated in Figs. l to 3. a combination of Vlive gears with spacer blocks between them forms twelve inlet and outlet chambers. A-similar'arrangement with six gears including four planetary gears, a sun gear and a ring gear would form fourteen inlet and outlet spaces as compared with only two inlet and outlet spaces formed by the ordinary gear pump having only twogears. What is more important, with the provisionr ofv inner and outer inlet and outlet spaces, the hydraulic forces produced during operation are substantially balanced with regard to each gear. Thus, no resultant force will act on the bearings of the sun gears by the pressure produced in the three uniformly spaced'inlet chambers and the three uniformly spaced outlet chambers adjacent the sun gear. The resultant of the forces of the fluid containedin the inlet chambers 4i and 5I adjacent the planetary gear 22 is small and the resultant of the hydraulic forces from the outlet chambers 46 and 52 acting on the bearings of the same planetary gear 22 is likewise small. This balance of hydraulic forces permits of better econy omy and efficiency of the hydraulic gear and mayBil, the shafts I9 and 33 of the motor rotate in clockwise direction, as indicated in Fig. 2.

In certain cases, it may be desirable to utilize only the inlet and outlet 4spaces -formed adjacent the sun gear or the ring gear. In some cases, it may be desirable to use an arrangement of this kind as a exible hydraulic connection, coupling, or torque converter, necessitating during 'some operating conditions a rotatable support for the outer casing. An arrangement embodying such features is illustrated in Figs. 4 and 5. This arrangement comprises a sun gear 55 secured to a shaft 66 supported on ball bearings 61. The sun gear meshes with four circumferentially uniformly spaced planetary gears 68, 69, 10 and 1|, each having a shaft 12 supported on both sides by ball bearings 13. The gears are enclosed in a casing which includes a cylinder 14 and end plates 15 and 16. The latter form supports for the ball bearings 61 and 13. The cylinder 14 has four inner projections orspacer blocks 11. 18, 19 and 88 located between adjacent planetary gears.

" Each block has an axial bore for receiving bolts 8| to fasten the end plates 15, 16 to the cylinder 14. The end plate 15 has a cylindrical projection 82 rotatably supported on a bearing or journal 83 heldon a pedestal 84. The pedestal also -formsa central journal bearing 85 for the shaft 66. The other end plate 16 has a similar cvlindrical projection 86 supported on a bearing 81 held on a pedestal 89 which forms also a central bearing 90 for a shaft 9|. The latter has an end portion 92 splined to a central opening of the end plate 16.

Each pedestal 84 and 89 has four ears 93 of which the two lower ones serve as supporting feet. The pedestals are held in spaced relation and securely fastened together by hollow spacer tubes 94 between corresponding ears 93 and bolts 95 projecting through the tubes 94 and the ears 93.

With an arrangement of this kind, rotation of the sun gear causes rotation of the planetary gears about their axes only, as long as the latter are free to rotate. If, however, the planetary gears are not free to rotate about their axes only, then rotation of the sun gear causes rotation of the casing including the cylinder 14 and the end plates 15. 16 about the sun gear.

Each spacer 11 to B0 has inner cylindrical surfaces concentric with the adjacent" gears. Thus. the spacer 11 has a irst cylindrical'surface 95 aseoloos concentric with the sun gear, a second cylindrical surface SLconcentric with the planetary gear 88 anda third cylindrical surface 98 concentric with the sun gear-69. Portions or inner walls of the spacers and the walls of the adjacent gears form spaces or chambers 99, |00, ||i|, |02, |03, |015, IGS and |06. Four of these eight spaces and chambers, in the present example the spaces with uneven numbers 99, lill, |03 and |05, are confnected through bores l to a chamber |08 formed by the pedestal 8B and Vconnected to a conduit 09. The four remaining spaces with even numbers |00, |02, |04 and |06 are connected by bores dit in the end plate l@ to a chamber formed Hzthe pedestal 89 and connected to a conduit To operate the arrangement as a pump, the conduit m9 is connected to a source of liquid (not shown) so that the liquid is conducted to the inlet or-supply chamber |08. Rotation of the shaftbt with the sun gear 55 clockwise, as,

the shafts se and si stationary. This may be accomplished by the provision of a brake.

' ful as a flexible hydraulic coupling ortorque converterl for connecting a drive shaft to a driven shaft. In the drawing I have shown vthe shaft 66 connectedl to a'drive Vshaft i |5by means of a clutch or coupling ||6 while the shaft 9| is connected to a driven shaft or a load ||1 by means of a clutch or coupling H8. 'Ihe drive shaft H5 may constitute part of a motor or power agency and the driven shaft lll may form part of a machine to be driven from the shaftll through the hydraulic torque converter or coupling arindicated by the arrows in Fig. 4, causes the liql uid thus conducted from the inlet chamber Hi8 through the bores itl into the inlet chambers or spaces 99, EN, |63 and |05 to be forced therev from into the outlet spaces "it, |02, |05 and its, whence the liquid is discharged throughy the operi-- ings il@ to the outlet or discharge chamber il i, l

to be discharged therefrom through a discharge conduit M2 to a consumer. During this opera tion the liquid supplied, for instance, to the inlet space @a is forced therefrom partly along the surface 96 of the spacer llinto the outlet space it!) and partly along the cylindrical surface 91| 3 of the spacer block 1l into the outlet space NB. Thus, as describedin connection with Figs. 1 to 3, the liquid supplied to each inlet space or chamf ber is discharged therefrom into the two nearest outlet spaces or chambers, -During this, operation the casing and the shaft 9| remain stationary unless the flow through the discharge conduit H2 is considerably restricted or, from another viewpoint, if the pressure head on the outlet side becomes sumciently high to cause a torque that will overcome the resistance of shaft 9|. In that case the shaft 9| and the casing rotate with a speed increasing with increasing pressure head in the discharge conduit i2. If the pressure head becomes innite, that is, if conduit l l2', for example, is completely closed, as by a. valve, the shaft 9| will rotate with a speed equal to the speed of the driven shaft 5G.

The arrangement mayl also be operated as a pump by driving the shaft 9| in counterclockwise direction (in Fig. 4) to rotate the casing with the planetary gears about the sun gear. If the casing in Fig. 4 is rotated in counterclockwise direction,

the operation of the arrangement asa pump is the same as that described above, the conduit |09 then constitutingl an inlet conduit and the conduit H2 a discharge conduit. y

During this operation the sun gear remains stationary until the pressure head in the `discharge conduit H2 exceeds a certain value whereupon the sun gear is rotated in counterclockwise direction at a speed increasing with increasing pressure head in the discharge conduit ||2.

rangement. If then the conduit |09 is connected to a source of liquid, the shaft al and the driven shaft ill connected thereto are rotated at a speed increasing with increasing pressure head in the conduit H2 and, vice-versa, with a decreasing speed upon decreasing pressure head in the conduit H2. If the conduit |2 is completely closed or shut o, the speed of the driven shaft lll becomes equal the speed of thev driving shaft operated as a motor. To this end one of the con--v duits M9, i l2 is connected to a source of-liquid under pressure. If' both shafts t6, @i are free to revolve with the same load on each, they will revolve in opposite directions at half speed. If

the torque resistance on one shaft increases, that shaft will 'slow down and the other shaft will increase in speed. If one shaft is held against rotation, the other shaft will revolve at full speed.

The arrangement of Figs. '4 and 5 may also operate as a variable speed motor. if the conduit l I2 is connected to a sourceof oil pressure and conduit tu@ is connected to an oil supply. If shaft H5 is connected to a power source the shaft ||1 can be connected Ato a power'absorber.

Then when shaft H5 is driven in one direction, say clockwise. and if fluid pressure is sufficiently high in conduit H2 to' overcome the torque transmitted, then the shaft i will revolve yat a higher speed than shaft H5 and in the same direction of rotation. It must do that to let 'the oil through that is being forced in through conduit l2. The speed increase of shaft lll over that of shaft H5 will be in vproportion to 'the quantity of oil forced in through 'conduit i l2. The oil in this case will flow throughconduit it to th'e oil supply.

if' the pressure in conduit 'l l2 is low enough, the

flow will be in conduit |09 and out conduit ||2.`

Having described the method of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, I desire to have it understood that the apparatus shown is only illustrative and that they invention may be carried out by other. means.

What I claim as new and desire to secure by Letters Patent of the United States is:

Hydraulic gear comprising a casing having a cylinder and end plates secured thereto said casing defining an inlet and an outlet, planetary gearing means disposed within the casing and including a sun gear, a shaft rotatably supporting the sun gear, a plurality of planetary gears mesh- To this-end I have diagrammatically indicated a ing with the sun gear, means rotatably supporting each planetary gear on the casing, and means including a shaft connected to one end plate and concentric bearings for rotatably supporting said shaft and end plate for rotatably supporting the 6" casing with the planetary gears about the sun gear, separate brakemeans to hold either one o! 

